In addition to the general definition, the term "popular front" also has a specific meaning in the history of Europe and the United States during the 1930s, and in the history of Communism and the Communist Party. During this time in France, the "front populaire" referred to the alliance of political parties aimed at resisting Fascism.

The term "national front", similar in name but describing a different form of ruling, using ostensibly non-Communist parties which were in fact controlled by and subservient to the Communist party as part of a "coalition", was used in Central and Eastern Europe during the Cold War.

Not all coalitions who use the term "popular front" meet the definition for "popular fronts", and not all popular fronts use the term "popular front" in their name. The same applies to "united fronts".

Cover of an American Communist pamphlet from the Popular Front period making use of patriotic themes under the slogan "Communism is the Americanism of the 20th Century."

In the weeks that followed Hitler's seizure of power in February 1933 the German Communist Party (KPD) and the Communist International clung rigidly to their view that the Nazi triumph would be brief and that it would be a case of "after Hitler - our turn". But as the brutality of the Nazi government became clear and there was no sign of its collapse, Communists began to sense that there was a need to radically alter their stance - especially as Hitler had made it clear he regarded the Soviet Union as an enemy state.

Georgi Dimitrov - who had humiliated the Nazis with his defence against charges of involvement in the Reichstag Fire - became general secretary of the Comintern in 1934 and by 1935, at the International's seventh congress the process of total reorientation reached its apotheosis with the proclamation of a new policy - "The People's Front Against Fascism and War". Under this policy Communist Parties were instructed to form broad alliances with all anti-fascist parties with the aim of both securing social advance at home and a military alliance with the USSR to isolate the fascist dictatorships. The "Popular Fronts" thus formed proved to be spectacularly successful in France and Spain, but had limited success elsewhere.

In May 1935, France and Soviet Union signed a defensive alliance and in August 1935, the 7th World Congress of the Comintern officially endorsed the Popular Front strategy.[3] In the elections of May 1936, the Popular Front won a majority of parliamentary seats (378 deputies against 220), and Léon Blum formed a government.[2] In Italy, the Comintern advised an alliance between the Italian Communist Party and the Italian Socialist Party, but this was rejected by the Socialists.

The Popular Front has been summarized by conservative historian Kermit McKenzie as

"...An imaginative, flexible program of strategy and tactics, in which Communists were permitted to exploit the symbols of patriotism, to assume the role of defenders of national independence, to attack fascism without demanding an end to capitalism as the only remedy, and, most important, to enter upon alliances with other parties, on the basis of fronts or on the basis of a government in which Communists might participate."[4]

This McKenzie asserted was a mere tactical expedient, with the broad goals of the communist movement for the overthrow of capitalism through revolution unchanged.[4]

The Popular Front period came to an end with the Molotov-Ribbentrop pact between Nazi Germany and USSR, at which point Comintern parties turned from a policy of anti-fascism to one of advocating peace.

Leon Trotsky and his supporters roundly criticised the Popular Front strategy. Trotsky believed that only united fronts could ultimately be progressive, and that popular fronts were useless because they included non-working class bourgeois forces such as liberals. Trotsky also argued that in popular fronts, working class demands are reduced to their bare minimum, and the ability of the working class to put forward its own independent set of politics is compromised. This view is now common to most Trotskyist groups. Left communist groups also oppose popular fronts, but they came to oppose united fronts as well.

In a book written in 1977, the Eurocommunist leader Santiago Carrillo offered a positive assessment of the Popular Front. He argued that in Spain, despite excesses attributable to the passions of civil war, the period of coalition government in Republican areas "contained in embryo the conception of an advance to socialism with democracy, with a multi-party system, parliament, and liberty for the opposition".[5] Carrillo however criticised the Communist International for not taking the Popular Front strategy far enough — specifically for the fact that the French Communists were restricted to supporting Leon Blum's government from without, rather than becoming full coalition partners.[6]

After World War II, most Central and Eastern European countries became de factoone-party states, but in theory they were ruled by coalitions between several different political parties who voluntarily chose to work together. For example, East Germany was ruled by a "National Front" of all anti-fascist parties and movements within parliament (Socialist Unity Party of Germany, Liberal Party, Farmers' Party, Youth Movement, Trade Union Federation, etc.). At legislative elections, voters were presented with a single list of candidates from all parties. In practice, however, only the Communist Party had any real power. By ensuring that Communists dominated the candidate lists, it effectively predetermined the composition of the legislature. All parties in the front had to accept the "leading role" of the Communist Party as a condition of being allowed to exist. By the 1950s, the non-Communist parties had pushed out their more courageous members and had been taken over by fellow travelers willing to do the Communists' bidding.

In the Republics of the Soviet Union, between around 1988 and 1992 (by which time the USSR had dissolved and all were independent), the term "Popular Front" had quite a different meaning. It referred to movements led by members of the liberal-minded intelligentsia (usually themselves members of the local Communist party), in some republics small and peripheral, in others broad-based and influential. Officially their aim was to defend perestroika against reactionary elements within the state bureaucracy, but over time they began to question the legitimacy of their republics' membership of the USSR. It was their initially cautious tone that gave them considerable freedom to organise and gain access to the mass media. In the Baltic republics, they soon became the dominant political force and gradually gained the initiative from the more radical dissident organisations established earlier, moving their republics towards greater autonomy and later independence. They also became the main challengers to Communist Party hegemony in Moldova, Ukraine, Armenia and Azerbaijan. A Popular Front was established in Georgia but remained marginal compared to the dominant dissident-led groups, because the April 9 tragedy had radicalised society and it was unable to play the compromise role of similar movements. In the other republics, such organisations existed but never posed a meaningful threat to the incumbent Party and economic elites.[7]

Popular Front of Finland Multiple governments that where formed in the country after the Communist Party of Finland was legalized in 1944; "Popular Front" governments stood usually as a coalition of the Social Democratic Party (which was though under strong anti-Communist leadership until 1963 and the strong Left orientation of the party from the late 1960's to late 1980's), the Centre Party, the Finnish People's Democratic League (cover organization of Communists and left-wing Socialists), and often also with minor Liberal parties like the Swedish People's Party and the Liberal People's Party, and led from 1944 to 1946 by Centre-right-wing Prime Minister Juho Kusti Paasikivi. "Popular Front" governments stood despite continuous electoral losses in 1944-1946 and during the Social Democratic Leftist period in 1966-1970, 1970-1971, 1975-1976 and 1977-1982. The main argument for this governments was good relationships with the Soviet Union, and the Centre-Right National Coalition Party was kept in opposition from 1966 to 1987, despite it's continuous approach to the Left in the 1970's and the 1980's.

All-Russia People's FrontОбщероссийский народный фронт; created in 2011 by then-Prime Minister Vladimir Putin in order to provide United Russia with "new ideas, new suggestions and new faces". This Front is intended to be a coalition between the ruling party and numerous non-United Russia nongovernmental organizations.